Switches in circuits alternate between activated or on states, where the switches are closed to conduct electric current from a source of the current to one or more loads, and deactivated or off states, where the switches are opened to prevent conduction of the electric current.
In some power supply circuits, such as circuits that supply on the order of several hundred to several thousand amps to power loads, power semiconductor switches such as thyristors are used to control the conduction of current to the loads. These thyristors may be formed from Silicon (Si) or Silicon Carbide (SiC) in order to reliably withstand the large currents supplied to the loads. These thyristors, however, can require the application of trigger currents having large slew rates to gates of the thyristors in order to activate the thyristors. In order to provide sufficiently large slew rates, however, very large current pulses may need to be applied to the gates of the thyristors.
These large current pulses can impart significant stress to the thyristors. This stress can lead to damage and/or destruction of the thyristors. Additionally, the circuitry components needed to supply such large current pulses can increase the cost and complexity of the gate drivers that supply the trigger currents to the gates of the thyristors.